Technical Field
The present invention relates to an occupant protection device.
Related Art
Airbag devices are known in which a bag is inflated so as to surround an occupant from the front and both sides, by fixing a gas supply pipe with the bag attached to a seatback, and supplying gas from an inflator to the bag through the gas supply pipe during a collision (see Japanese Patent Application Laid-Open (JP-A) No, 2000-344044).
Airbag devices are also known in which head airbags are inflated toward the front from left and right end portions of a headrest of a seat and joined together in front of the head of the occupant, while an auxiliary head airbag is inflated toward the front from a center portion of the headrest of a seat and is joined to the pair of head airbags (see JP-A. No. 2013-018378).
In the configuration of JP-A No. 2000-344044, the gas supply pipe is provided projecting out above the seatback, and so the appearance is negatively affected and the gas supply pipe becomes an interference when the vehicle seat is operated. These issues are resolved by a configuration in which the head airbags are housed inside the headrest, as described in JP-A No. 2013-018378. However, in the configuration of JP-A No. 2013-018378, it is difficult to secure joint strength between the pair of head airbags that are joined together after inflation and deployment, and to secure joint strength of the auxiliary head airbag with respect to the pair of head airbags.
As a countermeasure thereto, it would be conceivable to adopt a configuration in which an airbag, housed inside the headrest or the seatback, is inflated and deployed as a bag body so as to surround the head of an occupant from the seat front side and both seat width direction sides. In such cases, considering positional relationships between the head of the occupant, and a windshield and a side window in the vicinity thereof, a sufficiently long stroke to absorb energy might not be secured, depending on the collision direction, and so there is room for improvement from the perspective of occupant head protection performance, taking different collision directions into consideration.